I had a funny one a while ago... I was helping a guy get into the air. He had no rudders (a lot of guys don't!), so I was trying to talk him through the whole rudderless lift-off thing. Finally get him off the ground, we are soaring in the wide-blue... then he beelines for the first plane he sees!
"Don't shoot! Don't shoot!" I yell, knowing someone's training is going to get a new dimension. He bores right in, and I think "Great. Now I have to take this guy out...". I am closing in and notice the other half of the interrupted training session is closing on my 6. Oh well, if he gets me maybe they will feel better. He does.
I go to private and tell my killer I'm trying to control this guy. He laughs, and I tell him to waste him. He does.

The newbie laughs, and off they go to continue the fun.
At the end the new guy finally understands what happened. No real harm was done, but he had a few "defensive maneuvers" lessons from an impromptu trainer.
Goes to show sometimes the disruptive activity happens because some are so new they don't understand what they are doing.
